Box elder bugs

Q Spraying box-elder bugs with soapy water kills them almost instantly.
Why?

A No one is sure, but there are a couple of theories, according
to extension entomologist Jeff Hahn.

One is that the soap disrupts the hardened skin (cuticle) of
insects, breaking down the cell membranes. This results in the
insects becoming dehydrated, which kills them.

Others have suggested that soap blocks the breathing pores
(spiracles) and interferes with the insects' ability to respire.
Regardless of the reason, the soap water
needs to directly contact the box-elder bugs to be effective.
It also does not affect bugs that show up after you spray, so
you need to treat as often as you see box-elder bugs.

September 7, 2005

Soap is start to end of box-elder bugs

A reader writes: I'm curious as to whether there is anything
you can do with box-elder bug infestations. We get them every
year in September or late August around our front door. Can their
eggs (or however they hatch) be killed with an insecticide, or
is there any way to get rid of them before or just after they
begin hatching?

This time of year, box-elder bugs like to congregate on the
south and west walls before entering your house. Mix 1/2-cup of
laundry detergent in one gallon of water. With a hand sprayer
or hose end attachment, spray the bugs with the solution. Although
that only affects the bugs that are sprayed and more treatments
may be necessary, it is one way to reduce the numbers that get
into your house.

You can apply insecticides to the walls of your house, but
when you apply is critical, because applications are effective
for a limited time. If you decide to use insecticides, consider
calling a pest-control operator.
They will have access to stronger products
and have more experience with the problem. Indoors, dispose of
box-elder bugs by hand or with a vacuum cleaner. Insecticides
aren't necessary indoors because the bugs do not breed indoors
and are harmless to people.

Box-elder bugs do not lay eggs or reproduce in your home. But
they can reappear and become a nuisance in late winter or early
spring when warm weather causes them to move out of their hiding
places.

Now is the time to prevent a future infestation by sealing,
caulking and weather-stripping around windows, cable lines, dryer
vents and door frames. Screen vents and weep holes with 16-mesh
screening and repair any damaged roof soffits.

March 23, 2000

Box elder bugs are showing up in area homes

University of Minnesota Extension Service, Star Tribune
The unusually warm late winter days this year mean that some people
are finding active insects inside their homes. These insects were
previously sleeping away the winter, said Jeff Hahn, an entomologist
with the University of Minnesota Extension Service.

"The most common insects showing up have been box elder
bugs and multicolored Asian ladybird beetles.

"Often there are large numbers of these insects. They
entered buildings last fall seeking protected places to overwinter.
They often ended up in wall voids, attics and other unheated sites
to take up lodging until spring," Hahn said.

Warm winter days can fool insects into thinking that spring
has arrived, said Hahn. As they become active, many move into
the interior of homes, often becoming trapped around windows.

Unfortunately, once they get into walls and the attic, there
is no practical way to keep them from entering a home's interior.
The best control is to physically remove them when you see them,
by vacuuming or some other method.

The best time to control these insects is during late summer
and fall.

"By sealing cracks and other spaces and using insecticides
judiciously, you can prevent many of these nuisance insects from
entering your home," said Hahn.

August 30, 1999

Fixit: Trouble with box elder bugs? Soap them

Q I've started to see a lot of box elder bugs around my
house. I am afraid they will get indoors. How can I control them?
What do they eat?

A Box elder bugs typically feed on the seeds of the box elder
tree. Adult box elder bugs are orange and black and have wings
that cover the whole length of their bodies. The smaller bugs
without wings are the immature bugs or nymphs.

Sometimes large numbers of box elder bugs will congregate on
the sides of houses and buildings. This has nothing to do with
the color of the building or the nature of building material.
The bugs like sunshine and will congregate where it is warm and
sunny.

Right now they are satisfied to be outdoors and eat and reproduce.
In the fall months, that will change. They know that winter is
coming soon and will try to find shelter.

According to Jeffrey Hahn, assistant entomologist at the University
of Minnesota's Yard & Garden Line, some will try to seek protection
in your house. Those that get in will not live long, but those
that get into cracks and crevices will go into hibernation when
it gets cold, he said. These bugs will become active if their
hiding places warm up. That is why you can see a box elder bug
in the middle of winter. All the hidden bugs will become active
when the weather warms in the spring.

Box elder bugs are not easy to control, Hahn admits. But if
you want to keep them out of your house, prevent their entry this
fall by sealing and caulking every crack and crevice you can find.

A home remedy that is as effective as insecticides, Hahn said,
is a soap mixture consisting of 1/2 cup of laundry detergent powder
mixed in 1 gallon of water.

Hahn suggests applying this solution directly on the insects,
and thoroughly covering them. You can use a hand sprayer or squirt
bottle for this job. The soap mixture can stain some wood siding,
so be sure to try a test patch.

The more box elder bugs you prevent from coming indoors this
fall, the fewer problems you will have with them in the winter
and spring, Hahn said. He recommends that you spray as often as
the bugs are seen.

Box elder bugs are harmless, and Hahn recommends removing indoor
bugs by hand or vacuum. Be careful not to squash the bugs because
they can cause stains and smell bad.

February 17, 1998

Fixit: Mild weather brings boxelder bugs out of hiding

Q How can I get rid of boxelder bugs in the house? Now that
we've had a string of warm days, they are becoming active and
appearing in the house.

A Dispose of them by hand or with a vacuum cleaner. Insecticides
aren't necessary because the bugs do not breed indoors and are
harmless to people.

Take action in the fall to prevent a nuisance problem with
boxelder bugs during mild winter days, said Joseph Pedretii, entomology
technician, University of Minnesota Extension Service.

Prevent their entry into your home by sealing, caulking and
weather-stripping around windows, cable lines, dryer vents and
door frames. Screen vents and weep holes with 16-mesh screening
and repair any damaged roof soffits.

Cutting down a boxelder tree in your yard may have little effect
on the number of boxelder bugs in your home because it is such
a common tree and bugs can fly considerable distances looking
for an attractive area to spend the winter.

Boxelder bugs like to congregate on the south and west walls
in the fall before entering your house.

Mix 1/2 cup of laundry detergent in one gallon of water. With
a hand sprayer or hose end attachment, spray the bugs with the
solution. Although that only affects the bugs that are sprayed
and repeat treatments may be necessary, it is one way to reduce
the numbers that get into your house.

There are insecticides that you can apply to the walls of your
house, but time of application is critical because they are effective
for a limited time. If you decide to use them, consider
calling a pest-control operator. They will have access
to stronger products and have more experience with the problem.